Section 4: Soil and Water Conservation Engineering
Specific Energy, Critical Flow & Hydraulic Jump
Subtopic: Specific energy and critical flow
Question Statement:
In the specific energy curve shown, the critical depth in a rectangular flume is $y_c = 0.80\text{ m}$. Compute the critical velocity $v_c$ in $\text{m/s}$ at this minimum energy state for $g = 9.81\text{ m/s}^2$ (round off to two decimal places).
Answer Key:
2.8
Step-by-Step Solution & Explanation
At critical state in a rectangular channel, Froude number $Fr = 1$, so:
$v_c = \sqrt{g y_c} = \sqrt{9.81 \times 0.80} = \sqrt{7.848} \approx 2.80\text{ m/s}$.